Heat exchanger

ABSTRACT

Specified is a heat exchanger for an exchange of heat between a first fluid, in particular charge air or an exhaust gas, and a second fluid, in particular a coolant, having a block for the separate and heat-exchanging guidance of the first and second fluids, which block has a number of flow ducts which can be traversed by the first fluid and a housing which holds the flow ducts and which can be traversed by the second fluid, at least one casing cover which is flow-connected to the flow ducts, a base which is fixed to the casing cover and which is provided with one or with a plurality of passage openings for the flow ducts, wherein the base is composed of at least one first base part and a second base part.

CROSS-REFERENCE TO RELATED PATENT APPLICATIONS

The right of foreign priority is claimed under 35 U.S.C. § 119(a) basedon Federal Republic of Germany Application No. 10 2007 040 793.0, filedAug. 28, 2007, the entire contents of which, including thespecification, drawings, claims and abstract, are incorporated herein byreference.

BACKGROUND OF THE INVENTION

The invention relates to a heat exchanger for an exchange of heatbetween a first fluid and a second fluid, having: a block for theseparate and heat-exchanging guidance of the first and second fluids,which block has a number of flow ducts which can be traversed by thefirst fluid and a housing which holds the flow ducts and which can betraversed by the second fluid; at least one casing cover which isflow-connected to the flow ducts, a base which is fixed to the casingcover and which is provided with one or with a plurality of passageopenings for flow ducts. The invention also relates to a use of the heatexchanger.

In a known heat exchanger, a tank cover may be formed from deep-drawnsheet metal which is soldered to the block during the productionprocess. Although this has advantages in the high-temperature range,add-on components such as for example brackets or flanges for sensorsmust be produced as additional parts from sheet metal and connected tothe tank cover before the soldering process, which makes the productionprocess more complicated. Furthermore, a more complex tank shape cangenerally no longer be produced as a deep-drawn part, such that, in thiscase, production must take place by means of casting, and the tank covermust generally be welded to the block. Said type of tank has proven tobe comparatively expensive and complex to produce specifically in thecase of more complex structural shapes.

One cost-effective alternative to heat exchangers of said type is a heatexchanger of the type specified in the introduction, in which the tankhas a tank cover composed of plastic. Here, it is possible to realizecomparatively complex structural shapes, with it being by all meanspossible, with corresponding plastic materials and a correspondingdesign of the tank, to also realize higher temperature ranges. Examplesof tank covers composed of plastic are specified in DE 10 2004 051 207A1 and DE 10 2004 047 901 A1.

There are fundamentally different ways of attaching a plastic tank coverto the heat exchanger, such as for example connections as shown in WO2004/09457, FIG. 2 or DE 199 53 785 A1, FIG. 4.

DE 10 2005 012 761 A1 discloses a heat exchanger of the type specifiedin the introduction, having a housing composed of two side parts and twohousing covers, with the side parts being soldered to the block and thehousing cover being welded to the side parts. Furthermore, collectingtanks composed of plastic are mechanically connected, with theinterposition of a seal, to tube plates. The mechanical connection isachieved by bending lugs of the tube plates over the edge of thecollecting tank. Said type of heat exchanger has room for improvement.

What is desirable is a design of a heat exchanger which is comparativelysimple to produce and in which it is nevertheless possible to realizecomparatively complex structural shapes. This relates in particular tothe design of a base of the heat exchanger.

What is also desirable is a further advantageously improved connectionof a tank cover, in particular of a tank cover composed of anon-metallic material, to a metal part, to the base of a heat exchanger,preferably so as to provide an improved sealing action. Also desirableis an improvement to a housing of the heat exchanger.

SUMMARY OF THE INVENTION

The invention addresses this; it is an object of the invention tospecify a heat exchanger in which the base is of improved design. Inparticular, it is intended that a base is comparatively simple toproduce. It is also intended that the tank cover of a tank is connectedto the base in a particularly advantageous manner, and in particularthat a tank cover composed of a non-metallic material is connected in anadvantageous manner to the metal base, preferably so as to provide animproved sealing action. In particular, it is a further object of theinvention to specify a heat exchanger having an improved housing.

The object is achieved by means of a heat exchanger of the typespecified in the introduction, in which it is provided according to theinvention that the base is composed of a first base part and a secondbase part.

The invention has recognized that a two-part base can be of advantageousdesign, and a two-part base concept leads to simplified production ofthe base and at the same time to a greater degree of reliability in theproduction process. Firstly, the base should be of comparativelythick-walled design in the region of the passage openings for the flowducts, in particular in an inner region, in order to obtain a goodbundling capability and for example also to obtain good soldering of thebase and flow ducts. Secondly, it can be advantageous for the base to beof comparatively thin-walled design in relation thereto in a fasteningregion, in particular outer region, in particular for fixing a tankcover to the base by means of a corrugated slot flange. This has theadvantage that installation space can be saved and abrasive forces arekept comparatively low. By means of a corresponding punching process,the material can be punched out so as to form a fastening structure. Bymeans of the material reduction, for example in the edge region of abase, it is possible for a tank cover fastening to be designed with aconsiderably reduced installation space requirement. On the basis ofthis consideration, the invention has surprisingly found that, in theevent of significant material reductions, for example in the region of acorrugated slot flange—it is self-evident that a similar situationapplies for other, in particular mechanical, connection types such asfor example screw connections—the required pressing forces for materialreduction or mechanical connecting forces increase to a surprisinglygreat extent, such that, during production, the forces to be applied arecomparatively high, and/or in the worst case, a secure connection of atank cover to the base is no longer ensured. This fundamentally leads tocomparatively uneconomical production. Recognizing this, the concept ofthe invention proposes that a base be composed of a first base part anda second base part. A first base part is preferably designed to form aregion for passage openings of flow ducts. In addition, oralternatively, a second base part is preferably designed for connectingthe tank cover. This has the advantage that the region for passageopenings, formed for example as tube rim holes, can be designedindependently of a region of a tank cover connection, and can thereforebe used for different heat exchanger designs, for example for differentindirect charge-air coolers. The second base part, for example the outerregion of the base, may then—in accordance with a wide variety ofdesigns and material thicknesses for the respective application—bepreferably Tox clinched onto the first base part, for example the innerregion of the base. It is thus for example possible for differentmaterials and material thicknesses to be combined without problems.

Furthermore, this provides the advantage that add-on parts can beintegrated in the air tank in a practically cost-neutral fashion and, inthe case of complex air tank geometries, it is no longer necessary touse cast tanks—it is possible for plastic tanks to be used andadvantageously expediently connected, preferably mechanically fixed, tothe base or to the first and/or second base part according torequirements. Furthermore, the often-occurring potential risk in thecase of single-piece bases of premature damage to the material, or ofproduction-induced undesired material thinnings, is comparatively low.Said premature damage or material thinning can lead to a prematurefailure of the heat exchanger, or comparatively great materialdifferences in a single-piece base cannot always be producedcost-effectively. In the concept proposed here of a two-part ormulti-part base, said risk as a result of premature damage is reducedconsiderably, since the base production is considerably simpler and canalso be carried out in a cost-neutral fashion. It is thereby possible tocombine even large differences in material—be it the type of materialrequirement or a thickness of the material or other parameters—and isthereby possible to obtain inter alia installation space advantages.

It has proven to be particularly preferable that—as explained by way ofexample—the first base part and the second base part are mechanicallyfixed to one another. Furthermore, it has proven to be particularlyadvantageous within the context of one particularly preferred refinementfor a tank cover to be fixed to the base by means of one or moremechanical connections. As particularly preferred refinements, it ispossible to realize a mechanical connection as a screw connection, whichis referred to below as a first variant. Furthermore, a mechanicalconnection in the form of a slot flange, referred to as a secondvariant, is also suitable individually or in combination. The conceptaccording to the invention has proven to be particularly advantageousfor the case that the tank cover and the base, or in individual casesalso base parts, are composed of different materials.

In the above-specified refinement, the invention is based on theconsideration that a connection of a tank cover, composed in particularof a non-metallic material, for example a plastic, fiber compositematerial or a ceramic, should be comparatively secure, and should alsobe sufficiently flexible with regard to thermal relative movements ofthe base, which is composed preferably of metal, for example aluminum,and of the tank cover. The refinement has recognized that in particulara screw connection or a slot flange or a combination of a screwconnection with a slot flange is significantly more suitable for thispurpose than known connection types. A connecting type according to theconcept of the refinement therefore permits a particularlycost-effective connection of a tank cover, for example composed ofmetal, but in particular of a non-metallic material, to an otherwisemetallic design of heat exchanger, thereby permitting in particular alsomore complex tank shapes while avoiding complex production processes.

A heat exchanger of the type specified in the introduction may be formedin particular as a charge-air heat exchanger in which the first fluid ischarge air, or as an exhaust-gas heat exchanger in which the first fluidis an exhaust-gas. The first fluid may also be an exhaust-gas/charge-airmixture or similar fluid for charging an internal combustion engine. Thesecond fluid, in particular a coolant, is for example a water-basedcoolant or some other expedient coolant.

One particularly preferred refinement of the invention has proven to bea heat exchanger in the form of a charge-air heat exchanger, inparticular a charge-air cooler, which has the features according to theconcept of the invention. The above-listed problems have resultedspecifically in particular in air tanks, with indirect charge-aircooling having become increasingly established in the front of thevehicle on account of installation space restrictions in said region. Inthis connection, one refinement leads in a particularly preferred way tothe use of the heat exchanger according to the concept of the inventionas a charge-air cooler for the indirect cooling of charge air in acharge-air system for an internal combustion engine of a motor vehicle.

Furthermore, the concept according to the invention can also be realizedin a heat exchanger as described in the pending, not yet laid-openGerman patent application from the applicant with the file reference04-B-102 C. Said document specifies a heat exchanger of the typespecified in the introduction in which a base has at least one firstgroove into which the tank cover or a wall section of the tank cover ofthe tank extends. Here, a tank is to be understood to mean in particularthe tank cover, a seal and if appropriate the base. The documents ofsaid application are hereby incorporated by this reference into thecontent of disclosure of this application. It has been found that theconnection concept of a screw connection and/or of a slot flange betweenthe tank cover and base can be particularly advantageously realized inthe heat exchanger described in the cited application.

Further advantages of the concept of the invention emerge fromadvantageous refinements of the invention which can be gathered from thesubclaims.

As already mentioned above, the first base part is preferably formed asan inner base part and the second base part as an outer base part, withthe inner base part being surrounded at the periphery by the outer basepart. In this way, it is particularly preferably possible for the firstbase part to be designed to form passage openings for flow ducts and forthe second base part to be designed for preferably mechanically fixing atank cover to the base.

The first base part may fundamentally be formed in the manner of one ormore base plates which have the one or more passage openings. It is thusfor example possible for the base plate to also be realized merely inthe form of a frame which has a single passage opening. The base platemay also have a plurality of passage openings, for example, in apreferred first modification, passage openings arranged in one row. In asecond modification, passage openings arranged in two rows may also bepreferable. In principle, passage openings formed in more than two rowsare also possible. The region of the passage openings is preferablyformed with a greater wall thickness than a base plate edge region. Inthis regard, it has proven to be advantageous for the first base part,in particular the base plate, to have a podium which is elevated above abase plate edge region and which preferably has one or more passageopenings.

A passage opening is preferably formed in the manner of a passageopening which holds a flat tube, and is in particular formed so as to besubstantially rectangular.

In one particularly preferred embodiment, the second base part may beformed in the manner of one or more frame parts. A base frame part hasproven to be particularly suitable for forming a second base part forfixing, for example mechanically locking, a tank cover, for example bymeans of a slot flange and/or a screw connection. In this regard, in oneparticularly preferred embodiment, the second base part, in particular abase frame part, may be substantially L-shaped in a cross section.

A limb, which lies practically in a plane of the base plate, of theL-shaped cross section can have at least one bead. A bead of said typehas proven to be particularly suitable for holding an end edge of a wallpart of a tank cover. In a further preferred embodiment, it is alsopossible for two beads, in particular beads formed on different sides,to be provided on the base frame part. The other bead formed in additionto the above-mentioned bead preferably serves to hold a wall region of ahousing part, in other words to hold a housing edge.

A limb, which lies transversely with respect to the plane of the baseplate, of the L-shaped cross section preferably has at least one slotwhich permits the formation of a slot flange. Particularly suitable inthis regard are slots which are spaced apart from one another runningaround the entire periphery, which slots are for example punched. In onemodification, slots of said type may in principle also be provided in asecond base part with an L-shaped cross section.

The first base part and the second base part may fundamentally havedifferent materials or else the same materials. It is particularlypreferably provided that the first base part and the second base parthave different material parameters, in particular different materialthicknesses. The concept of the invention has recognized—as explainedabove—that different material thicknesses are preferable for the fixingof the flow ducts in passage openings of the first base part and for theconnection of the tank cover or in particular for the locking of a tankcover by means of the second base part. Said advantage is realizedparticularly effectively following the concept of the inventionaccording to the present refinement.

The first and the second base parts may be fixed to one another by meansof one or more cohesive connections. Soldered or welded connections, forexample, are particularly suitable. In one particularly preferredrefinement, however, it is provided that the first and second base partsare fixed to one another by means of one or more mechanical, inparticular form-fitting connections. In one very particularly preferredrefinement, the base parts are Tox clinched to one another. It hassurprisingly been found that such mechanical connection types or othersimple mechanical connection types nevertheless fix the base parts toone another in a sufficiently secure manner.

Furthermore, the tank cover can be fixed to the base by means of one ormore cohesive connections—soldered or welded connections areparticularly suitable here too. Furthermore, however, it has proven tobe particularly preferable for the tank cover to be fixed to the base bymeans of one or more mechanical, in particular form-fitting,connections—particularly preferably—as already explained above—as one ormore screw connections and/or slot flanges.

The base is advantageously composed of a metal, in particular ofaluminum. This permits sufficient thermal stability and also anadvantageous attachment of the flow ducts into the passage openings ofthe base.

In order to ensure a further improved sealed connection of the tankcover, one particularly preferred refinement provides that a seal isfixed between the base and the tank cover.

It is particularly advantageously provided that the base and/or the tankcover has a bead which is advantageously designed to hold the seal. Inparticular, the bead is arranged in a base edge region and/or in a tankcover edge region.

Within the context of the above-specified refinements, it has proven tobe particularly effective for sealing the tank if an end side of thetank cover or a wall section of the tank cover and/or of the baseextends along the bead.

The above-specified refinements are particularly suitable, preferably inorder to improve a sealing behavior, to fix the base and the tank coverrelative to one another—in a bead. One or more beads may optionally bearranged on the tank cover. An end side of the base then advantageouslyextends along the bead. One or more beads are preferably arranged on thebase, and an end side of the tank cover advantageously extends along thebead. In other words, in one particularly advantageous delimitation fromthe prior art, one or more beads are utilized to obtain improved andmore sealing fixing of the base and tank cover relative to one another.

According to one particularly improved first modification, it isprovided that the tank cover or a wall section of the tank cover and/orof the base makes contact, in an abutting fashion, by means of an endside against the base, in particular in such a way that the end sideengages over the bead. In other words, the width of the end side isgreater than the width of the bead.

The first modification of the invention specified above has proven, inparticular with respect to a screw connection, to be particularlyeffective, in particular with regard to its sealing behavior, but is notrestricted thereto. The screw connection may fundamentally be realizedin a variety of ways. One refinement of the invention provides aparticularly reliable design of the screw connection. Within the contextof the concept of the invention, a refinement has proven to beparticularly advantageous in which the base has a number of eyes forholding in each case one screw connection. An eye may be arranged inparticular at a corner and/or on a side of the base. The attachment ofeight eyes—in each case one at each corner and on each side of thebase—has proven to be particularly effective. It is very generallypossible for two adjacent eyes to have a spacing which lies in the rangebetween 40 and 90 mm, preferably between 50 and 70 mm. The number ofeyes is fundamentally dependent on the dimensions of the base. Thestated spacing ranges have proven to be particularly advantageous forpreferred base dimensions, and form an expedient compromise betweenstability and material expenditure.

The production process can be simplified if a lock nut is provided onthe base or on the tank to form the screw connection.

According to one particularly preferred second modification, it isprovided that an end side of the cover or of a wall section of the coverand/or of the base engages into a bead. The second modification hasproven to be particularly effective within the context of a slot flange,preferably for a corrugated slot flange, but is not restricted thereto.In this way, it is possible to realize a particularly advantageoussealing action, and the slot flange can be used in a particularlyspace-saving manner. The slot flange is advantageously designed as acorrugated slot flange, since this has proven to be reliable and fallswithin the scope of previous production concepts.

In one particularly preferred refinement of the invention, thepossibility for a material saving has been created in that a basethickness advantageously decreases in the radially outward directionacross a bead. The base thickness at least at the bead base ispreferably smaller than at a point of the base which is situated furtherinward along the radius. The abrasion forces for the slot flange orcorrugated slot flange are correspondingly smaller, on account of thereduced material thickness, than in other designs. One particularlyadvantageous compromise between the material expenditure and stabilityis provided if the ratio of a greatest base thickness to a smallest basethickness is in the range between 2:1 and 4:1.

The base is preferably fixed to the housing, for example by means of acohesive or mechanical connection, or by means of some other connection,suitable for the fastening of the base, of the base to the housing. Inparticular, the base holds the flow ducts in the one or more passageopenings. This ensures sufficient retention of the flow ducts on thebase, and the block is arranged in the housing in a particularlyadvantageous manner.

The housing preferably has side walls which extend along a flowdirection, and is formed in a plurality of parts. This permitsparticularly simple assembly of the block in the housing and of the heatexchanger overall. It has been found to be particularly advantageousaccording to the refinement that at least one housing part forms ahousing edge, that is to say is integrally formed. In this way, it ispossible to avoid leaks as a result of connecting points of housingparts at a housing edge, and the assembly of the housing is madeconsiderably simpler. At least one housing part, at least in regions,preferably integrally forms a first and a second side wall which arealigned at an angle with respect to one another. This has the advantagethat, in contrast to the prior art, housing side walls need no longer beprovided separately, but rather are provided integrally in a singlehousing part. In particular, this reduces the number of housing parts.

It is preferable, according to a first modification, for at least onehousing part to be of U-shaped design, for example so as to provide acover wall and at least a part of a first side wall and at least a partof a second side wall of the housing. The housing is preferably formedfrom two U-shaped housing parts. The two housing parts are preferablycorrespondingly formed, such that an entire housing casing can be formedin a simple manner by means of said housing parts. It can beadvantageous in particular for the two U-shaped housing parts to besymmetrical or practically identical, which considerably simplifies theproduction process. To form a housing casing, and in particular in thecase of U-shaped housing parts, a parting edge of housing parts ispreferably arranged in the region of a side wall.

In a second modification, it has proven to be advantageous for at leastone housing part to be of L-shaped design, for example as cover wall andside wall, which are formed with the single-piece housing part, of thehousing. The housing can be formed overall from two L-shaped housingparts. In particular, the two L-shaped housing parts are correspondinglyformed or largely symmetrical or identical, which considerably reducesthe production expenditure. Preferably within the context of the secondmodification, it has proven to be advantageous to arrange a parting edgeof housing parts in the region of a housing edge.

Within the context of one preferred refinement of the invention, theblock has a first arrangement and a second arrangement of flow ducts,with the first arrangement and the second arrangement being arranged onopposite sides of an intermediate base. The integrity and stability ofthe heat exchanger is considerably improved in this way, and it isnevertheless possible to provide a comparatively large flow crosssection for the first fluid, for example an exhaust gas or charge air.

An intermediate base may be arranged parallel to and/or substantially ina plane spanned by the parting edges of housing parts. This has provento be advantageous in particular in the case of U-shaped housing parts,in which a parting edge is arranged in the region of a side wall. Thisadvantageously permits the arrangement of an intermediate basepractically centrally and parallel to the side walls and in the planespanned by the parting edges of the U-shaped housing parts.

It is fundamentally advantageous within the context of theabove-specified refinement that opposite parting edges of the housingparts form a gap, in particular with a gap width of 1 mm to 2 mm. Theselection of the gap width is important in particular during thesoldering of the components, in particular for the formation of thesolder meniscus, since adequate soldering is not ensured if the gap istoo large or if the gap is too small.

According to a preferred first modification of said refinement, anintermediate base can engage into a gap formed by opposite parting edgesof the housing parts. This stabilizes the multi-part housing inconnection with the block. Furthermore, it is particularly preferablypossible to utilize the intermediate base which is situated in the gapto seal the housing parts with respect to one another. In a preferredsecond modification of said refinement, a web can cover parting edges ofthe housing part, and can in particular be arranged at the outside onthe housing. The measures provided in addition or alternatively to thefirst modification can likewise be utilized to stabilize the multi-parthousing. A web may preferably have a bead, in particular a bead which isdesigned additionally for stiffening. It is particularly preferable in arefinement of said second modification for a bead of the web to bedesigned so as to engage into a gap formed by opposite parting edges ofthe housing parts.

In one advantageous refinement of the invention, at least two componentsof the heat exchanger are soldered to one another.

In one advantageous refinement of the invention, all of the componentsof the heat exchanger with the exception of the at least one tank cover,in particular the two tank covers, are soldered to one another.

Overall, according to the above-specified refinements relating to thehousing, a particularly stable housing is provided which can beassembled using comparatively few parts. The above-explained measuresfor the design and arrangement of the parting edges of the housing partsadditionally lead to a particularly preferable further stabilization orreinforcement of the multi-part housing.

While the invention has proven to be particularly expedient within thecontext of a use of the heat exchanger in the form of a charge-air heatexchanger, in particular charge-air cooler, for example for the indirector for the direct cooling of charge air in a charge-air system for aninternal combustion engine of a motor vehicle, and is to be understoodin this sense, and while the invention is described in detail below onthe basis of examples from this field, it should nevertheless be clearthat the concept described here and as claimed is likewise expedientwithin the context of other applications which lie outside the examplesexplicitly stated and other applications which are not explicitlyspecified. For example, the proposed concept of the invention islikewise suitable for the use of a heat exchanger as an exhaust-gas heatexchanger, in particular exhaust-gas cooler, for example for exhaust-gascooling in an exhaust-gas recirculation system of an internal combustionengine of a motor vehicle or as an auxiliary heater for heating theinterior space of a motor vehicle. Also possible is a use as an oilcooler, in particular for cooling engine oil and/or transmission oil, ora use as a refrigerant cooler or refrigerant condenser in a refrigerantcircuit of an air-conditioning system of a motor vehicle. In thisconnection, the invention also encompasses an exhaust-gas recirculationsystem for an internal combustion engine, having an exhaust-gasrecirculation line, a compressor and a heat exchanger in the form of anexhaust-gas heat exchanger, in particular cooler, according to theconcept of the invention. The invention also encompasses a charge-airsupply system for an internal combustion engine, having a charge-airintake line, an air filter, a compressor and a heat exchanger accordingto the concept of the invention in the form of a charge-air heatexchanger, in particular cooler.

Exemplary embodiments of the invention are now explained below on thebasis of the drawing. Said drawing is intended to illustrate theexemplary embodiments not necessarily to scale; the drawing is in factshown in schematized and/or slightly distorted form where appropriatefor explanation. With regard to enhancements of the teaching which canbe directly gathered from the drawing, reference is made to the relevantprior art.

Here, it is to be taken into consideration that various modificationsand changes relating to the shape and details of an embodiment may becarried out without departing from the general idea of the invention.The features of the invention disclosed in the above description, in thedrawing and in the claims can be essential both individually and also incombination for the refinement of the invention. The general idea of theinvention is not restricted to the precise shape or the detail of thepreferred embodiment shown and described below, or restricted to asubject matter which would be restricted in relation to the subjectmatter claimed in the claims. Where dimensional ranges are specified,values which fall within the specified limits are also intended to bedisclosed as limit values and usable and claimable in any desiredmanner. The drawing shows, in detail, different embodiments according tothe concept of the invention, with a realization of the block of theheat exchanger in detail as described in the above-specified Germanpatent application from the applicant having proven to be advantageous.

Further objects, features and advantages of the present invention willbecome apparent from the detailed description of preferred embodimentsthat follows, when considered together with the accompanying figures ofdrawing.

BRIEF DESCRIPTION OF THE DRAWINGS

In detail, in the drawing:

FIG. 1 shows, in view A, a first base part in the form of a base plateand, in view B, a second base plate in the form of a base frame part,for forming a base in one particularly preferred embodiment of a heatexchanger according to the second variant;

FIG. 2 shows the base, formed by the base plate and the base frame ofFIG. 1, in a perspective view in view A and as an external plan view inview B,

FIG. 3 shows one particularly preferred embodiment of a heat exchangeraccording to the first variant;

FIG. 4 shows an enlarged perspective partially sectioned illustration ofthe base region of the embodiment of FIG. 3;

FIG. 5 shows an exploded illustration of FIG. 4;

FIG. 6 shows a sectioned illustration of the detail of a screwconnection in the embodiment as per FIG. 3 to FIG. 5;

FIG. 7 shows a particularly preferred embodiment according to the secondvariant;

FIG. 8 shows an enlarged perspective partially sectioned illustration ofthe embodiment from FIG. 7;

FIG. 9 shows an exploded illustration of FIG. 8;

FIG. 10 shows a perspective partially sectioned illustration of thedetail of a corrugated slot flange in FIG. 8;

FIG. 11 and FIG. 12 show a sectioned illustration of the detail of thecorrugated slot flange of the embodiment in FIG. 7 to FIG. 10;

FIG. 13 shows a perspective illustration of a further preferredembodiment of a heat exchanger according to the first or second variantof the invention, in which, in a first modification, the housing isformed from two U-shaped housing parts and is reinforced by means of aweb (shown in an exploded illustration) with a stiffening bead;

FIG. 14 shows a perspective illustration of the heat exchanger fromFigure 13;

FIG. 15 shows a perspective illustration of yet a further preferredembodiment of the heat exchanger similar to that as per FIG. 13 and FIG.14, with, in contrast, an intermediate base engaging into a gap formedby opposite parting edges of U-shaped housing parts;

FIG. 16 shows an exploded illustration of the heat exchanger shown inFIG. 15;

FIG. 17 shows a perspective illustration of yet a further embodiment ofa heat exchanger according to the first or second variant of theinvention, in which, in a second modification, the housing is formedwith L-shaped housing parts and an angled parting edge;

FIG. 18 shows an exploded illustration of the housing of the heatexchanger shown in FIG. 18.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Below, the same reference symbols are used for identical or functionallyequivalent parts.

FIG. 1 shows, in view A, a first base part 15.1 which is formed as aninner base part in the form of a base plate with a plurality of passageopenings 17 for flow ducts 5. Here, the passage openings 17 are in thepresent case arranged in two rows and are formed by a podium which iselevated above a base plate edge region 61, specifically as a relativelythick inner base region 63 which is formed within the base plate edgeregion 61. Here, a passage opening 17 is of substantially rectangulardesign in order to be able to hold a flow duct 5 in the form of a flattube.

The second base part 15.2 shown in view B in FIG. 1 is formed as anouter base part in the form of a single base frame part, and in thepresent case, has an L-shaped cross section. The free area 65 of thebase frame part corresponds substantially to the area of the podium 63,and can thus hold the passage openings 17, which are guided through thepodium 63, with inserted flow ducts 5.

In the present case, that limb 67 of the L-shaped cross section whichlies transversely with respect to the plane of the base plate has slots31 which are spaced apart from one another running around the entireperiphery, which slots 31 are punched so as to form a slot flange,explained with reference to FIG. 7 to FIG. 12, into the limb 67.Situated between the slots 31 is material 35 of the limb 67, whichmaterial 35 is utilized to form the slot flange.

The other limb 69, which lies in the plane of the base plate, of theL-shaped cross section can, in a first modification, serve, at itsunderside (not visible in view B of FIG. 1), as a contact surface forthe base plate edge region 61. The inner region 63 of the base plate isthen formed in a closely-fitting manner with respect to the opening 65of the base frame part. The outer edge of the base plate edge region 61then adjoins a border, which merges into a bead between the limb 69 andthe limb 67, of the limb 69. In this way, the base plate—as it isinserted from below in the first modification—is fixed into the baseframe part in a closely fitting manner even against lateraldisplacement.

FIG. 2 shows—in a perspective view in view A and as a plan view in viewB—a base 15′, as will be explained in more detail with reference to FIG.7 to FIG. 12, firstly for connecting a tank cover of a heat exchanger 20and secondly for holding a plurality of passage openings 17 for the flowducts 5.

In the present case, the first base part 15.1 and the second base part15.2 are fixed to one another by means of a plurality of Tox clinchedpoints 71. It should be understood that several further relativearrangements of the first base part 15.1 and second base part 15.2 arepossible over and above the first modification, and furthermore, otherform-fitting or cohesive connections which are not shown here for fixingthe first base part 15.1 and second base part 15.2 to one another may beexpedient according to requirement and expenditure. A Tox clinchedconnection with a plurality of Tox clinched points 71 has proven to beparticularly preferable in the present case. Here, it is possible inparticular—as explained here on the basis of a second modification—for abase plate to lie with its base plate edge region 61 on the limb 69 ofthe base frame part—that is to say, the base plate can be placed intothe base frame part. This has the advantage that the limb 69 may also beof rectilinear design, and a bead 21′ is nevertheless formed between thelimb 67 and the base plate—specifically by the upright edge 73 of thebase plate. The first base part 15.1 and the second base part 15.2 maybe fixed to one another by means of Tox clinching in this case too.Furthermore, in the second modification illustrated here, there is theadvantage that the base part 15.1 can serve to support the tank cover11′. Furthermore, the base edge part may be formed with a bead 21′ orelse so as to be flat in the limb 69. During the formation of the slotflange with the limb 67, the latter is then additionally pressed ontothe base plate region 61, such that the base plate can, in a mannershown in FIG. 7 to FIG. 12, be fixed by means of an upright end side 25′of a wall region 28 of a tank cover 11′ to the base plate edge region 61and to the slot flange.

Overall, said type of base 15′ which is composed, as per FIG. 1 and FIG.2, of a first base part 15.1 and a second base part 15.2, results in theadvantage that the second base part 15.2, which is formed as a base edgepart, can be produced effectively and also with a (practicallyarbitrary) material thickness which is advantageous for the slot flange.The second base part may be produced with the above-mentioned bead 21′or else without the latter—in which case a deep-drawing process isdispensed with. A bead-like groove, which can be utilized for theplacement of a seal or the like, is nevertheless generated as a resultof the upright edge 73. Also generated is a small projecting length ofthe base, which can be produced comparatively effectively, withcomparatively good support for a tank cover 11. The two-part designtherefore enables stable tank support. Furthermore, the first base part15.1, which is formed as a base plate, can be produced in a particularlysimple and reliable fashion. It has been found that the Tox clinchingprocess has, in a particularly positively surprising manner, proven tobe non-critical in process terms for the assembly of the first andsecond base part 15.1, 15.2, and the costs in the case of a two-partdesign as per FIG. 1 and FIG. 2 are neutral in relation to a likewisepossible single-part design—such as is explained for example in thefiled but not yet laid-open application under the applicant's filereference 06-B-239-A.

Without returning to the detail of the two-part design of the base 15′,a base according to the two-part design in FIG. 1 and FIG. 2 is used inthe embodiments of a base shown in FIG. 7 to FIG. 12.

It should nevertheless be noted that even a base which is not providedwith a slot flange—for example a base 15 formed with a screw connection,as per FIG. 3 to FIG. 6—can be formed, as a base not shown here yetcomposed similarly in principle, with a first base part—even identicalto the base part 15.1—and a second base part correspondingly modified inrelation to the base part 15.2 for the screw connection. In such a case,too, the first base part 15.1, which is formed as a base plate, can ifappropriate be placed in a closely-fitting manner into a frame-likesecond base part 15.2, with an L-shaped cross section, wherein eyes forconnecting a tank cover 11 can be provided on the second base part15.2—as can be seen from FIG. 3 to FIG. 6—instead of the slots 31.

FIG. 3 shows a heat exchanger 10 in the form of a charge-air cooler forindirect charge-air cooling, which charge-air cooler can be used in acharge-air system for an internal combustion engine. A charge-air system(not illustrated in any more detail) also has a charge-air intake line,an air filter and a compressor. The heat exchanger 10 represents aparticularly preferred embodiment of the first variant, according towhich a tank cover 11 is fixed to a base 15 by means of a plurality ofscrew connections 19.

As can be seen by viewing FIG. 3 and FIG. 4 together, the heat exchanger10 has a block 1 which is provided for the separate and heat-exchangingguidance of a first fluid in the form of charge air 3 and also of acoolant (not illustrated in any more detail). For this purpose, theblock 1 has a number of flow ducts 5 which can be traversed by thecharge air 3, and a housing which holds the flow ducts 5 and which canbe traversed by the coolant. In the present case, the charge-air cooler10 has two tanks 9, 9′, of which the front tank 9 is illustrated in moredetail in FIG. 4 to FIG. 6. The two tanks 9, 9′ are flow-connected tothe flow ducts 5 and have tank cover 11, 11′ which is designeddifferently in detail corresponding to the connections for the chargeair 3. In this embodiment, the two tank covers 11, 11′ are formed fromplastic, with the front cover 11 with a single integrally formeddiffuser arrangement 13 for the charge-air connection being illustratedin more detail. A two-part base 15—similar to that of FIG. 1 and FIG.2—is fixed to the cover 11, which two-part base 15 has passage openings17 which are clearly illustrated in FIG. 5 and flow ducts 5 which areassigned to said passage openings 17.

In a modified embodiment, the heat exchanger may also be embodied as aheat exchanger which is traversed, correspondingly, by exhaust gasinstead of charge air 3.

In the embodiment illustrated in FIG. 3 to FIG. 6, according to thefirst variant of the invention, the tank cover 11, 11′ is fixed by meansof a plurality of screw connections 19, illustrated in more detail inFIG. 6, to the base 15. Here, the base 15 has a bead 21 which, in thepresent case, runs all the way around the base 15, in which bead 21 isheld a seal 23, in the present case in the form of an annular seal.

As can be seen from FIG. 6 viewed together with FIG. 3 to FIG. 5, theend side 25 of the tank cover 11, 11′ extends along the bead 21 and,here, makes contact in an abutting fashion with the base 15, with theend side 25 engaging over the bead 21. In this way, the seal 23 ispressed by means of the end side 25 into the bead 21, so as to generatevery effective sealing between the base 15 and the tank cover 11. Thescrew connections 19 are in the present case formed in each case by ascrew 19A and a lock nut 19B which is held in a screw eye 19C. As isclearly shown in FIG. 3 to FIG. 5, in each case one screw eye 19C isarranged in each case at one corner or at the centre of a side of thebase 15. The screw connection is also secured by means of an annularflange 19D between the lock nut 19B and the screw 19A. The screwconnection 19 serves to exert a contact pressure between the tank cover11 and the base 15 on the seal 23, which seal 23 expands in the bead 21on account of the contact pressure and provides effective sealingbetween the tank cover 11 and the base 15.

The screw connections 19C are spaced apart uniformly with respect to oneanother; in the present case, the spacing should be approximately 50 to80 mm. For screwing on, lock nuts 19B are arranged either on that sideof the base which faces toward the block 1 or on the tank 9, 9′. In thepresent case, the screw 19A is inserted through a tank foot in the formof a metal sleeve on the base 15, and is screwed to the nut 19B behindthe base 15.

In the screw connection 19, the groove width in the base 15 isapproximately 3 mm. The seal 23, which is 2 mm wide, is pressed into thebead 21. The bead 21, 21′ is locally thickened at some points, in thepresent case every 30 mm, up to the bead dimension in order to positionthe seal 23.

FIG. 7 shows a different charge-air cooler 20, likewise for indirectcharge-air cooling as described in more detail above with reference tothe charge-air cooler 10, in which, in the present case, according toone preferred embodiment of the second variant, the tank cover 11 on thesecond base 15′ is fixed—identically to FIG. 1 and FIG. 2—by means of aslot flange connection 26 as a corrugated slot flange. Identicalreference symbols have been used for corresponding parts of thecharge-air coolers 10 and 20.

In contrast to the embodiment described with reference to FIG. 3 to FIG.6, in the embodiment of a charge-air cooler 20 shown here, the tankcover 11′ is fixed to the base 15′ by means of a corrugated slot flange26. For this purpose, a seal 23′ is placed into the bead 21′ which isformed in the present corrugated slot flange 26, which seal 23′, afterthe tank cover 11′ is placed on, is pressed into the bead 21′ in asealing fashion by means of the end side 25′, which engages into thebead 21′, of the tank cover 11′. Particularly advantageous sealing ofthe tank 9, 9′ is obtained in this way. The wall section 28, which formsthe end side 25′ of the tank cover 11′, of the tank cover 11′ merges atone end into the above-described air connection, which is embodied as adiffuser 13, and at the other end, the wall section 28 has, along aheight H of the bead 21′, ribs 27 which are semi-cylindrical in shapeand which are arranged with a spacing 29. Situated opposite the ribs 27is in each case one slot 31 of a flank 33 which is situated opposite thewall section 28. Situated opposite the spacing 29 is that material 35 ofthe flank 33 which is situated between the slots 31, said material beingaluminum in the present case. Said material 35 can, during the closureof the slot flange 26, be pressed into the spacing 29 between the ribs27 so as to form the corrugated slot flange. At least some of thecomponents of the heat exchanger 10 are soldered, in particularNocolok-soldered, to one another. In another exemplary embodiment, allthe components of the heat exchanger 10 with the exception of the atleast one tank cover, in particular the tank covers, are soldered, forexample Nocolok-soldered, to one another.

In the illustration shown in FIG. 12—applicable equally to a heatexchanger 10 and a heat exchanger 20—it is also illustrated that a basethickness decreases in the radially outward direction across the bead21′—in the present case, from the greatest value D in the region of theopenings 17 for the flow ducts 5, in the present case tubes, via a valueD′ in the region of the bead 21′, to a smallest value d in the region ofthe outer flank 33 of the bead 21′, the material 35 of which flank isflanged to form the corrugated slot flange 26. In the present case, thethickness of the base 15′ varies from D=4 mm to d=1.5 mm, that is tosay, overall, it is possible in embodiments of this type to reduce thebase material by 50 to 70%. It has also been found that it is alsopossible for this purpose to form the thickness at the lowest point T ofthe bead 21′ to be even in the range of the smallest value d. It isotherwise possible regardless of the embodiment described here for thetransition from the large thickness D to the thin thickness d to be ofany desired design.

The described design of the bead 21′ has the advantage that the base 15′permits effective tube and flow duct soldering with a good bundlingprocess in the region of the openings 17 with the large thickness D. Incontrast, on account of the smallest value d of the small materialthickness in the region of the corrugated slot flange 26, a particularlyinstallation-space-saving concept which keeps abrasive forces low isobtained. For example, the material 35 to be flanged can be displacedduring the course of a punching process. As a result of the materialreduction in the region of the flank 33, the fastening of the tank 9, 9′can be designed with a considerably reduced installation spacerequirement. At least some of the components of the heat exchanger 10are soldered, in particular Nocolok-soldered, to one another. In anotherexemplary embodiment, all the components of the heat exchanger 10 withthe exception of the at least one tank cover, in particular the tankcovers, are soldered, for example Nocolok-soldered, to one another.

The embodiments, explained on the basis of FIG. 13 to FIG. 18, of a heatexchanger in the form of a charge-air cooler 30, 40, 50 showadvantageous examples of a design of a housing 7 as is generally shownin the above-described FIG. 3 to FIG. 12. The modifications of a housing37, 47, 57 shown in FIG. 13 to FIG. 18 can if required be used for ahousing 7 of FIG. 3 to FIG. 12. The embodiments of a heat exchanger 30,40, 50 described in FIG. 13 to FIG. 18 are illustrated merely by way ofexample as embodiments according to the second variant of the invention,in which a tank cover of the heat exchanger 30, 40, 50 is fixed to thebase as a slot flange. The statements made with regard to FIG. 13 toFIG. 18 can be applied equally to an embodiment (not shown) of a heatexchanger in which the tank cover is fixed to the base by means of ascrew connection. Overall, the features (both individually and also incombination) disclosed in FIG. 3 to FIG. 12, in particular relating tothe fixing of the tank cover to the base, can be combined, and usedaccording to the application, with the features (individually or incombination) disclosed in FIG. 13 to FIG. 18, in particular relating tothe design of a housing 37, 47, 57. In this respect, in the exemplaryembodiments, the same reference symbols have been used for identicalparts or functionally equivalent parts. At least some of the componentsof the heat exchanger are soldered, in particular Nocolok-soldered, toone another. In another embodiment, all the components of the heatexchanger with the exception of the at least one tank cover, inparticular the tank covers, are soldered, for example Nocolok-soldered,to one another.

FIG. 13 shows a heat exchanger 30 in the form of a charge-air cooler asan embodiment according to the second variant of the invention, similarto the heat exchanger 20 described in FIG. 7. Said heat exchanger 30again has a block 1 with a number of flow ducts 5 which are traversed bycharge air 3 and which are hold in a housing 37 which can be traversedby the coolant. As is explained on the basis of FIG. 7 to FIG. 12, tanks9, 9′ are flow-connected to the flow ducts 5 and have a tank cover 11,11′ which is designed differently in detail corresponding to theconnections for the charge air 3. Said tank covers 11, 11′ are in eachcase fixed to the base 15, 15′ in the way explained with regard to FIG.7 to FIG. 12. The base 15, 15′ is fixed to the housing, with the flowducts 5 extending through passage openings 17 illustrated in more detailin FIG. 9.

The housing 37, which is illustrated in a perspective view in FIG. 14and as an exploded illustration in FIG. 13, has two cover walls 36 andtwo side walls 38, with a cover wall 36 being aligned substantially atright angles to the side wall 38. An upper housing part 37.1, which isU-shaped in the present case, forms a first and a second upper housingedge 39.1, 39.2, while a second, lower housing part 37.2 forms a first,lower housing edge 39.3 and a second lower housing edge 39.4 (notillustrated). The upper housing 37.1 is formed correspondingly—with theexception of coolant connections 41, 42, 43—so as to be substantiallyidentical to the lower housing part 37.2. Via the coolant connections41, 42, 43, coolant 4 is, in a way not illustrated in any more detail,supplied to and discharged from the interior of the housing 37 in orderto purge the flow ducts 5. In the present case, the entire housingcasing of the housing 37 is formed by means of the upper housing part37.1 and the lower housing part 37.2 The parting edges 44.1 and 44.2 ofthe upper housing part 37.1 and of the lower housing part 37.2 are inthe present case arranged in the region of a side wall 38 of the housing37 and are situated opposite one another so as to form a gap 45. For thesealing closure of the housing 37, the gap 45 is covered by a web 46,with a stiffening bead 46.1 of the web engaging into the gap 45. Inaddition to sealing closure of the housing 37, the attachment of the web46 leads to the stability of the housing 37, which is alreadycomparatively high as a result of the single-piece design of the upperhousing part 37.1 and of the lower housing part 37.2, being improved yetfurther. At least some of the components of the heat exchanger aresoldered, in particular Nocolok soldered, to one another. In anotherexemplary embodiment, all the components of the heat exchanger with theexception of the at least one tank cover, in particular the tank covers,are soldered, for example Nocolok soldered, to one another.

FIG. 15 shows a perspective illustration, and FIG. 16 shows an explodedillustration, of a further embodiment of a heat exchanger 40 in the formof a charge-air cooler, the housing 47 of which is again formed from anupper housing part 47.1 and a lower housing part 47.2, with the housingparts 47.1 and 47.2 being practically identical to the housing parts37.1 and 37.2 of FIG. 13—of U-shaped design. The opposing parting edges44.1, 44.2 of the housing parts 47.1, 47.1 again form a gap 45, intowhich an intermediate base 48, illustrated in more detail in FIG. 16,engages. Here, the block 1 has a first arrangement 1.1 and a secondarrangement 1.2 of flow ducts 5, with the first arrangement 1.1 and thesecond arrangement 1.2 being arranged on opposite sides of theintermediate base 48. At least some of the components of the heatexchanger are soldered, in particular Nocolok soldered, to one another.In another exemplary embodiment, all the components of the heatexchanger with the exception of the at least one tank cover, inparticular the tank covers, are soldered, for example Nocolok soldered,to one another.

It can be seen from the illustrations in FIG. 13 to FIG. 16 that a heatexchanger 30, 40 having the U-shaped housing parts 37.1, 37.2, 47.1,47.2 can be bundled in a particularly simple manner, wherein in theembodiment illustrated in FIG. 13 and FIG. 14, a web 46 is utilized forsealing the gap 45 between the parting edges 44.1 and 44.2, while in theembodiment illustrated in FIG. 15 and FIG. 16, an intermediate base 48is utilized for sealing the gap 45. The housing parts 37.1, 37.2 and47.1, 47.2 are in the present case soldered to oneanother—alternatively, or in addition, the housing parts may also bewelded to one another. In a way which is not illustrated, the housingparts may also additionally or alternatively be mechanically joined toone another.

FIG. 17 shows a further embodiment of a heat exchanger 50, in which ahousing 57 is formed, in the manner illustrated in FIG. 16, with anupper L-shaped housing part 57.1 and a lower L-shaped housing part 57.2.Again, each L-shaped housing part 57.1, 57.2 forms a housing edge 59.1and 59.2, and in each case one cover wall 56 and side wall 58 of thehousing 57. In the embodiment shown in FIG. 17 and FIG. 18, a cover wall56 is provided in each case with stiffening areas and/or openings 51,while in the embodiment illustrated in FIG. 13 to FIG. 16, stiffeningareas 52 and/or openings are formed on a side wall 38. At least some ofthe components of the heat exchanger are soldered, in particular Nocoloksoldered, to one another. In another exemplary embodiment, all thecomponents of the heat exchanger with the exception of the at least onetank cover, in particular the tank covers, are soldered, for exampleNocolok soldered, to one another.

As can be seen from FIG. 18, the first housing part 57.1 and the secondhousing part 57.2 are again formed correspondingly, such that the entirehousing casing of the housing 57 is finished by assembling said firsthousing part 57.1 and second housing part 57.2 at a parting edge 54.1,54.2. In the present case, in each case diagonally opposing partingedges 54.2 are provided with a bent lug 55 which—as well as stiffeningthe L-shaped housing part 57.1, 57.2—also serves for an improvedform-fitting fastening of the housing parts 57.1, 57.2. In this regard,in each case one parting edge 54.1 is pushed under the lug 55 of theopposite parting edge 54.2 in order to provide the housing casing of thehousing 57. Here, the housing parts 57.1, 57.2 are soldered to oneanother. At least some of the components of the heat exchanger aresoldered, in particular Nocolok soldered, to one another. In anotherexemplary embodiment, all the components of the heat exchanger with theexception of the at least one tank cover, in particular the tank covers,are soldered, for example Nocolok soldered, to one another.

Overall, the embodiments of a housing 37, 47, 57 illustrated in FIG. 13to FIG. 18 permit the realization of a multi-part and neverthelessparticularly stable housing.

In summary, specified is a heat exchanger 10, 20, 30, 40, 50, inparticular a charge-air heat exchanger or exhaust-gas heat exchanger,for an exchange of heat between a first fluid, in particular charge air3 or an exhaust gas, and a second fluid, in particular a coolant, whichheat exchanger has: separate and heat-exchanging guidance, in the block1, of the first and second fluids, which block 1 has a number of flowducts 5 which can be traversed by the first fluid and a housing 7, 37,47, 57 which holds the flow ducts 5 and which can be traversed by thesecond fluid; at least one casing cover 11, 11′ which is flow-connectedto the flow ducts 5, a base which is fixed to the casing cover 11, 11′and which is provided with one or with a plurality of passage openings17 for flow ducts 5. In order to obtain an advantageous connection ofthe tank cover 11, 11′ to the base 15, 15′, in particular in the case ofthe tank cover 11, 11′ and base 15, 15′ being composed of differentmaterials, and to nevertheless permit expedient production and flexibleuse of the base, the invention provides that the base 15, 15′ iscomposed of at least one first base part and a second base part, inparticular, the tank cover 11, 11′ is fixed to the base 15, 15′ by meansof one or more connections as screw connections 19 and/or slot flanges26.

The foregoing description of preferred embodiments of the invention hasbeen presented for purposes of illustration and description only. It isnot intended to be exhaustive or to limit the invention to the preciseform disclosed, and modifications and variations are possible and/orwould be apparent in light of the above teachings or may be acquiredfrom practice of the invention. The embodiments were chosen anddescribed in order to explain the principles of the invention and itspractical application to enable one skilled in the art to utilize theinvention in various embodiments and with various modifications as aresuited to the particular use contemplated. It is intended that the scopeof the invention be defined by the claims appended hereto and that theclaims encompass all embodiments of the invention, including thedisclosed embodiments and their equivalents.

1. Heat exchanger for an exchange of heat between a first fluid, inparticular charge air or an exhaust gas, and a second fluid, inparticular a coolant, having: a block for the separate andheat-exchanging guidance of the first and second fluids, which block hasa number of flow ducts which can be traversed by the first fluid and ahousing which holds the flow ducts and which can be traversed by thesecond fluid; at least one casing cover which is flow-connected to theflow ducts, a base which is fixed to the casing cover and which isprovided with one or with a plurality of passage openings for the flowducts, wherein the base is composed of at least one first base part anda second base part.
 2. Heat exchanger according to claim 1, wherein thefirst base part is formed as an inner base part and the second base partis formed as an outer base part, with the inner base part beingsurrounded at the periphery by the outer base part.
 3. Heat exchangeraccording to claim 1, wherein the first base part is formed in themanner or one or more base plates which have the one or more passageopenings.
 4. Heat exchanger according to claim 1, wherein the first basepart, in particular a base plate, is flat.
 5. Heat exchanger accordingto claim 1, wherein the first base part, in particular base plate, has apodium which is elevated above a base plate edge region and whichpreferably has one or more passage openings.
 6. Heat exchanger accordingto claim 1, wherein passage openings are formed in one row, two rows ormore than two rows.
 7. Heat exchanger according to claim 1, wherein aflow duct is formed in the manner of a flat tube, in particular, apassage opening is formed so as to be substantially rectangular.
 8. Heatexchanger according to claim 1, wherein the second base part is formedin the manner of one or more base frame parts.
 9. Heat exchangeraccording to claim 1, wherein the second base part, in particular a baseframe part, is substantially L-shaped in cross section.
 10. Heatexchanger according to claim 1, wherein a limb, which lies in a plane ofthe base plate, of an L-shaped cross section has at least one bead, inparticular two beads formed on different sides.
 11. Heat exchangeraccording to claim 1, wherein a first bead is designed to hold an endside of the tank cover or a wall section of the tank cover.
 12. Heatexchanger according to claim 1, wherein a second bead is designed tohold a housing edge.
 13. Heat exchanger according to claim 1, wherein atleast one slot, in particular slots which are spaced apart from oneanother running around the entire periphery, are arranged, in particularpunched, in a limb lying transversely with respect to the plane of thebase plate, preferably so as to form a slot flange.
 14. Heat exchangeraccording to claim 1, wherein the second base part, in particular a baseframe part, is I-shaped in cross section.
 15. Heat exchanger accordingto claim 1, wherein the first base part and the second base part havedifferent materials and/or different material thicknesses from oneanother.
 16. Heat exchanger according to claim 1, wherein the first basepart and the second base part are fixed to one another by means or oneor more cohesive, in particular soldered or welded, connections. 17.Heat exchanger according to claim 1, wherein the first base part and thesecond base part are fixed to one another by means of one or moremechanical, in particular form-fitting, connections.
 18. Heat exchangeraccording to claim 1, wherein the first base part and the second basepart are Tox clinched to one another.
 19. Heat exchanger according toclaim 1, wherein the tank cover is fixed to the base by means of one ormore cohesive, in particular soldered or welded, connections.
 20. Heatexchanger according to claim 1, wherein the tank cover is fixed to thebase by means of one or more mechanical, in particular form-fitting,connections.
 21. Heat exchanger according to claim 1, wherein the tankcover is fixed to the base by means of one or more a) screwconnection(s) and/or b) slot flange(s).
 22. Heat exchanger according toclaim 1, wherein the tank cover and the base and/or at least one basepart are composed of different materials.
 23. Heat exchanger accordingto claim 1, wherein the base and/or at least one base part are/iscomposed of a metal, in particular of aluminum.
 24. Heat exchangeraccording to claim 1, wherein the tank cover is composed of a non-metal,in particular of a plastic, a fiber-composite material, a ceramic ormixtures thereof.
 25. Heat exchanger according to claim 1, wherein thetank cover and a seal are parts of a tank.
 26. Heat exchanger accordingto claim 1, wherein a seal is fixed between the base and/or a base part,in particular a base frame part and the tank cover.
 27. Heat exchangeraccording to claim 1, wherein the base and/or a base part, in particulara base frame part, has a bead, in particular in a base edge region. 28.Heat exchanger according to claim 1, wherein a seal is arranged in thebead.
 29. Heat exchanger according to claim 1, wherein an end side ofthe tank cover or of a wall section of the tank cover extends along thebead.
 30. Heat exchanger according to claim 1, wherein the tank cover ora wall section of the tank cover makes contact, in an abutting fashion,by means of an end side against the base and/or a base part, inparticular a base plate or a base frame part, in particular, the endside engages over the bead.
 31. Heat exchanger according to claim 1,wherein an end side of the tank cover or of a wall section of the tankcover engages into the bead.
 32. Heat exchanger according to claim 1,wherein the base has a number of eyes for holding the screw connection,in particular at a corner and/or on a side of the base and/or of a basepart, in particular of a base frame part.
 33. Heat exchanger accordingto claim 32, wherein two adjacent eyes have a spacing in the range from40 to 90 mm, in particular 50 to 70 mm.
 34. Heat exchanger according toclaim 1, wherein a lock nut is provided on the base or on the tank coverto form the screw connection.
 35. Heat exchanger according to claim 1,wherein the flange is formed as a slot flange, in particular as acorrugated slot flange.
 36. Heat exchanger according to claim 1, whereina base thickness decreases in the radially outward direction across abead, preferably with a ratio of greatest base thickness to smallestbase thickness in the range between 2:1 and 4:1.
 37. Heat exchangeraccording to claim 1, wherein a base thickness at least at one bead baseis smaller than at a point of the base which is situated further inwardalong a radius.
 38. Heat exchanger according to claim 1, wherein thebase is fixed to the housing and/or the base holds the flow ducts in theone or more passage openings.
 39. Heat exchanger according to claim 1,wherein the housing has side walls which extend along a flow directionand is formed in a plurality of parts, with at least one housing partforming a housing edge.
 40. Heat exchanger according to claim 1, whereinat least one housing part, at least in regions, integrally forms a firstand a second side wall which are aligned at an angle with respect to oneanother.
 41. Heat exchanger according to claim 1, wherein at least onehousing part is of U-shaped design, preferably, the housing is formedfrom two, in particular correspondingly formed, U-shaped housing parts.42. Heat exchanger according to claim 1, wherein a parting edge ofhousing parts is arranged in the region of a side wall.
 43. Heatexchanger according to claim 1, wherein at least one housing part is ofL-shaped design, preferably, the housing is formed from two, inparticular correspondingly formed, L-shaped housing parts.
 44. Heatexchanger according to claim 1, wherein a parting edge of housing partsis arranged in the region of a housing edge.
 45. Heat exchangeraccording to claim 1, wherein the block has a first arrangement and asecond arrangement of flow ducts, with the first arrangement and thesecond arrangement being arranged on opposite sides of an intermediatebase.
 46. Heat exchanger according to claim 1, wherein an intermediatebase is arranged parallel to and/or substantially in a plane spanned bythe parting edges of housing parts.
 47. Heat exchanger according toclaim 1, wherein opposite parting edges of housing parts form a gap. 48.Heat exchanger according to claim 1, wherein an intermediate baseengages into a gap formed by opposite parting edges of the housingparts.
 49. Heat exchanger according to claim 1, wherein a web coversparting edges of housing parts, and is in particular arranged at theoutside on the housing.
 50. Heat exchanger according to claim 1, whereina web has a bead, in particular a stiffening bead.
 51. Heat exchangeraccording to claim 1, wherein a bead of a web engages into a gap formedby opposite parting edges of housing parts.
 52. Heat exchanger accordingto claim 1, wherein housing parts are cohesively and/or mechanicallyjoined to one another.
 53. Heat exchanger according to claim 1 in theform of a charge-air heat exchanger, in particular cooler.
 54. Heatexchanger according to claim 1 in the form of an exhaust-gas heatexchanger, in particular cooler.
 55. Heat exchanger according to claim1, wherein at least two components of the heat exchanger are soldered toone another.
 56. Heat exchanger according to claim 1, wherein all of thecomponents of the heat exchanger with the exception of the at least onetank cover, in particular the two tank covers, are soldered to oneanother.
 57. Use of a heat exchanger according to claim 1 as acharge-air cooler for the direct or indirect cooling of charge air in acharge-air system for an internal combustion engine of a motor vehicle.58. Use of a heat exchanger according to claim 1 as an exhaust-gascooler for the direct or indirect cooling of exhaust gas in anexhaust-gas recirculation system for an internal combustion engine of amotor vehicle.